1. Field
The present invention generally relates to a ureteral calculus suction instrument, and particularly to a ureteral calculus suction instrument of the type referred to in claim 1.
2. Prior Art
Ureteroscopes serve to work in the ureter, the channel within the body which connects the kidneys to the bladder. Because this channel is very narrow, the diameter of the shaft of the ureteroscope must not be more than a maximum of 4-5 mm.
The very narrow cross-section of the shaft must accommodate the image conductor of an optical system. This exhibits at the distal end of the shaft a lens, from which an image conductor runs along the length of the shaft, consisting of rod lenses located one behind another, a light-conducting fibre bundle, or a video cable attached to a video camera.
With known ureteroscopes, a channel is arranged in the remaining very narrow cross-section, which serves as a working channel to accommodate instruments such as, for example, a lithotripter, for example in the form of a laser fibre, but which can also be used as a suction channel. The ureteroscope can therefore be used as a generic ureteral calculus suction instrument, in order to extract by suction calculus fragments produced with the lithotripter.
A disadvantage with the known generic ureteral calculus suction instruments is the suction of calculus fragments through the suction channel, which is very narrow, with a cross-section in the size range of the calculus fragments, as a result of which blockages occur due to calculus fragments becoming wedged in the suction channel. As well as this, the size of the calculus fragments which can be suctioned off is limited by the diameter of the suction channel.